We will continue to study the binding kinetics of organic ligands, principally fatty acids, to serum transport proteins, principally human serum albumin. Using rapid dielectric measurements, made possible by pulse response analysis, with stopped flow techniques, association and dissociation rates of binding are determined. From these, as well as form calorimetric data and equilibrium binding constants, complete thermodynamic description of the two-step-binding of fatty acids is possible, including complete thermodynamic specification of the activated transition state. Such information is used to infer characteristics of the mechanism of the binding process. Comparative studies, and competition studies are to be done similarly. This work is an effort to study the mechanisms involved in a large class of binding reactions which is currently the subject of extensive research largely on an empirical level. Fatty acid binding to serum albumin has direct effects, and competitive as well as facilitative interaction with binding of other metabolites, hormones, and drugs, which have been recognized as medically significant in treatment of diabetes, numerous metabolic disorders and myocardial infarct, as well as in the estimation of dose response in the administration of nearly all therapeutic organic compounds.